led earlier, the mortality-reducing measures will be increas-
to influencing population growth and size, at least until
ical technology permit a major extension of the human life
;s might influence population growth and size through inter-on, but their potential importance as population control mea-itemporary world are limited, because in most instances the ie possible international flows is dwarfed by the magnitude of ease. Furthermore, a deliberate encouragement of out-migra-to be an undesirable policy from the economic standpoint strongly selective nature of modern migratory movements, 'ith valuable skills are most likely to migrate.)
'lity Control Policies
isfactory evaluation of policies aimed at controlling fertility 1 on a comparison of the costs and benefits, both direct and i policies. However the vast majority of writings on this sub-3mewhat different, narrower terms. Either because the possi-oseful interference with a fertility trend is not contemplated ie assumption that the economic cost of such interference is usual approach is merely to analyze the economic conse-jothetical or observed differences in fertility, bypassing the v those differences are to be explained in the first place. Thus, irting from a given initial situation, in the fashion of the by-[y of Coale and Hoover (1), alternative courses of fertility over ecified as affecting the same initial population, and the conse-ous economic indicators may be worked out by plugging the jlation trends into an appropriate model describing the work-omy in question.
ice of such a procedure to a full cost-benefit analysis of popu-programs is evident. Once the net economic benefits of a / are worked out (as a rule tacitly assuming that the reduction 10 economic costs), the level of those benefits may be related :s of any proposed scheme that is capable of engineering the on specified in the calculation. A rate of return to investment ne may then be calculated. The scheme will be supported or Miomic grounds depending on whether the rate of return so gher or lower than the return that may be earned in feasible . of the funds involved. While somewhat awkward, this two-corresponds to the logical, and to the historical, sequence of of contemporary proposals for controlling fertility. In the first jst centers around the economic effects of alternative courses